Hostname: page-component-8448b6f56d-xtgtn Total loading time: 0 Render date: 2024-04-17T16:59:51.544Z Has data issue: false hasContentIssue false

Revision of the first therocephalian, Theriognathus Owen (Therapsida: Whaitsiidae), and implications for cranial ontogeny and allometry in nonmammaliaform eutheriodonts

Published online by Cambridge University Press:  15 January 2016

Adam K. Huttenlocker
Affiliation:
Department of Biology, University of Utah, and Natural History Museum of Utah, Salt Lake City, Utah 84112, USA 〈ahuttenlocker@gmail.com〉
Fernando Abdala
Affiliation:
Evolutionary Studies Institute, University of Witwatersrand, Johannesburg, Republic of South Africa 〈nestor.abdala@wits.ac.za〉

Abstract

Historically, the whaitsiid therocephalian Theriognathus Owen was one of the earliest described nonmammalian therapsids, its morphology helping to link phylogenetically the Paleozoic synapsids of North America and southern Africa to their mammalian successors. However, decades of taxonomic over-splitting and superficial descriptions obscured the morphologic diversity of the genus, hindering its utility as a study system for the evolution of synapsid cranial function as well as its biostratigraphic significance in the Late Permian of southern Africa. Here, we revise the status and provenance of all the known specimens of Theriognathus from South Africa, Tanzania, and Zambia. We present both qualitative and quantitative support for the presence of a single morphospecies as proposed by some authors. Proportional differences in skulls that were previously ascribed to different morphotypes (‘Aneugomphius,’ ‘Notosollasia,’ ‘Moschorhynchus,’ and ‘Whaitsia’) are largely size-related and allometric trends are considered here in the context of jaw function and prey prehension. Our results suggest that the single species, Theriognathus microps, represented one of the most abundant Late Permian therocephalians in southern Africa and is consequently a potentially useful biostratigraphic marker for the upper Cistecephalus-lower Dicynodon Assemblage Zone transition (i.e., late Wuchiapingian). The wide range of preserved sizes in conjunction with recent paleohistological evidence supports that individuals spent much of their lives in an actively-growing, subadult phase. Later Dicynodon Assemblage Zone records (e.g., upper Balfour Formation) are unconfirmed as the genus was likely replaced by other theriodont predators (e.g., Moschorhinus) leading up to the Permo-Triassic boundary in the Karoo Basin of South Africa.

Type
Articles
Copyright
Copyright © 2016, The Paleontological Society 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Abdala, F., 2007, Redescription of Platycraniellus elegans (Therapsida, Cynodontia) from the Lower Triassic of South Africa, and the cladistic relationships of eutheriodonts: Palaeontology, v. 50, p. 591618.CrossRefGoogle Scholar
Abdala, F., and Giannini, N.P., 2000, Gomphodont cynodonts of the Chañares Formation: the analysis of an ontogenetic sequence: Journal of Vertebrate Paleontology, v. 20, p. 501506.CrossRefGoogle Scholar
Abdala, F., and Giannini, N.P., 2002, Chiniquodontid cynodonts: systematic and morphometric considerations: Palaeontology, v. 45, p. 11511170.CrossRefGoogle Scholar
Abdala, F., Rubidge, B.S., and van den Heever, J., 2008, The oldest therocephalians (Therapsida, Eutheriodontia) and the early diversification of Therapsida: Palaeontology, v. 51, p. 10111024.CrossRefGoogle Scholar
Abdala, F., Jasinoski, S.C., and Fernandez, V., 2013, Ontogeny of the Early Triassic cynodont Thrinaxodon liorhinus (Therapsida): dental morphology and replacement: Journal of Vertebrate Paleontology, v. 33, p. 14081431.CrossRefGoogle Scholar
Abdala, F., Jashashvili, T., Rubidge, B.S., and van den Heever, J., 2014a, New material of Microgomphodon oligocynus (Eutherapsida, Therocephalia) and the taxonomy of southern African Bauriidae, in Kammerer, C.F., Angielczyk, K.D., and Fröbisch, J., eds., Early Evolutionary History of the Synapsida: Dordrecht, Springer, p. 209231.CrossRefGoogle Scholar
Abdala, F., Kammerer, C.F., Day, M.O., Jirah, S., and Rubidge, B.S., 2014b, Adult morphology of the therocephalian Simorhinella baini from the Middle Permian of South Africa and the taxonomy, paleobiogeography and temporal distribution of the Lycosuchidae: Journal of Paleontology, v. 88, p. 11391153.CrossRefGoogle Scholar
Allin, E.F., 1975, Evolution of the mammalian middle ear: Journal of Morphology, v. 147, p. 403437.CrossRefGoogle ScholarPubMed
Angielczyk, K.D., and Schmitz, L., 2014, Nocturnality in synapsids predates the origin of mammals by over 100 million years: Proceedings of the Royal Society B, v. 281, doi:10.1098/rspb.2014.1642.Google ScholarPubMed
Angielczyk, K.D., Steyer, J.S., Sidor, C.A., Smith, R.M.H., Whatley, R.L., and Tolan, S., 2014, Permian and Triassic dicynodont (Therapsida: Anomodontia) faunas of the Luangwa Basin, Zambia: taxonomic update and implications for dicynodont biogeography and biostratigraphy, in Kammerer, C.F., Angielczyk, K.D., and Fröbisch, J., eds., Early Evolutionary History of the Synapsida: Dordrecht, Springer, p. 93138.CrossRefGoogle Scholar
Attridge, J., 1956, The morphology and relationships of a complete therocephalian skeleton from the Cistecephalus zone of South Africa: Proceedings of the Royal Society of Edinburgh, v. 116, p. 5993.Google Scholar
Barghusen, H.R., 1968, The lower jaw of cynodonts (Reptilia, Therapsida) and the evolutionary origin of mammal-like adductor jaw musculature: Postilla, v. 116, p. 149.Google Scholar
Boonstra, L.D., 1934, A contribution to the morphology of the mammal-like reptiles of the suborder Therocephalia: Annals of the South African Museum, v. 31, p. 215267.Google Scholar
Botha, J., and Smith, R.M.H., 2006, Rapid vertebrate recuperation in the Karoo Basin of South Africa following the end-Permian extinction: Journal of African Earth Sciences, v. 45, p. 502514.CrossRefGoogle Scholar
Botha, J., Abdala, F., and Smith, R., 2007, The oldest cynodont: new clues on the origin and early diversification of Cynodontia: Zoological Journal of the Linnean Society, v. 149, p. 477492.CrossRefGoogle Scholar
Brink, A.S., 1954, On the Whaitsiidae, a family of therocephalian mammal-like reptiles: Transactions of the Royal Society of South Africa, v. 34, p. 4359.CrossRefGoogle Scholar
Brink, A.S., 1956, On Aneugomphius ictidoceps Broom and Robinson: Palaeontologia Africana, v. 4, p. 97115.Google Scholar
Brink, A.S., 1980, On the genus Theriognathus Owen (including Whaitsia, Notosollasia, Alopecopsis, Notaelurops, Moschorhynchus and Aneugomphius): Annals of the Geological Survey of South Africa, v. 14, p. 137.Google Scholar
Brink, A.S., and Kitching, J., 1951, CXIII.—Some theriodonts in the collection of the Bernard Price Institute: Annals and Magazine of Natural History, v. 4, p. 12181236.CrossRefGoogle Scholar
Broom, R., 1910, Observations on some specimens of South African fossil reptiles preserved in the British Museum: Transactions of the Royal Society of South Africa, v. 2, p. 1925.CrossRefGoogle Scholar
Broom, R., 1920, On some new therocephalian reptiles from the Karroo beds of South Africa: Proceedings of the Zoological Society, v. 3, p. 343353.CrossRefGoogle Scholar
Broom, R., 1925, On some carnivorous therapsids: Records of the Albany Museum, v. 25, p. 309326.Google Scholar
Broom, R., 1930, On the structure of the mammal-like reptiles of the suborder Gorgonopsia: Philosophical Transactions of the Royal Society B, v. 218, p. 345371.Google Scholar
Broom, R., 1931, Notices of some new genera and species of Karroo fossil reptiles: Records of the Albany Museum, v. 4, p. 161166.Google Scholar
Broom, R., 1932, The Mammal-like Reptiles of South Africa and the Origin of Mammals: H.F. & G. Witherby.Google Scholar
Broom, R., 1935, On some new genera and species of Karroo fossil reptiles: Annals of the Transvaal Museum, v. 18, p. 5572.Google Scholar
Broom, R., 1936, On some new genera and species of Karroo fossil reptiles, with notes on some others: Annals of the Transvaal Museum, v. 18, p. 349386.Google Scholar
Broom, R., and Robinson, J.T., 1948, Some new fossil reptiles from the Karoo Beds of South Africa: Proceedings of the Zoological Society of London, v. 118, p. 392407.CrossRefGoogle Scholar
Crompton, A.W., 1955, A revision of the Scaloposauridae with special reference to kinetism in this family: Navorsinge van die Nasionale Museum, v. 1, p. 149183.Google Scholar
Crompton, A.W., 1963, The evolution of the mammalian jaw: Evolution, v. 17, p. 431439.CrossRefGoogle Scholar
Emerson, S.B., and Bramble, D.M., 1993, Scaling, allometry and skull design, in Hanken, J., and Hall, B.K., eds., The Skull v. 3: Functional and Evolutionary Mechanisms: Chicago, University of Chicago Press, p. 384415.Google Scholar
Flores, D.A., Abdala, F., and Giannini, N., 2010, Cranial ontogeny of Caluromys philander (Didelphidae: Caluromyinae): a qualitative and quantitative approach: Journal of Mammalogy, v. 91, p. 539550.CrossRefGoogle Scholar
Hammer, Ø, and Harper, D.A.T., 2005, Paleontological Data Analysis: Oxford, Blackwell Publishing, 351 pp.CrossRefGoogle Scholar
Hammer, Ø., Harper, D.A.T., and Ryan, P.D., 2001, PAST: Paleontological statistics software package for education and data analysis: Palaeontologia Electronica, v. 4, p. 19.Google Scholar
Haughton, S.H., 1918, Some new carnivorous Therapsida, with notes upon the braincase in certain species: Annals of the South African Museum, v. 12, p. 175216.Google Scholar
Haughton, S.H., and Brink, A.S., 1954, A bibliographical list of Reptilia from the Karroo beds of Africa: Palaeontologica Africana, v. 2, p. 1187.Google Scholar
Heever, J. van den., 1994, The cranial anatomy of the early Therocephalia (Amniota: Therapsida): Annals of the University of Stellenbosch, v. 1, p. 159.Google Scholar
Hopson, J.A., and Barghusen, H., 1986, An analysis of therapsid relationships, in Hotton, N., MacLean, P.D., Roth, J.J., and Roth, E.C., eds., The Ecology and Biology of Mammal-like Reptiles: Washington, D.C., Smithsonian Institution Press, p. 83106.Google Scholar
Huene, F. von., 1950, Die Theriodontier des ostafrikanischen Ruhuhu-Gebietes in der Tübinger Sammlung: Neues Jahrbuch für Geologie und Paläontologie Beilage-Band, v. 92, p. 47136. [in German].Google Scholar
Huttenlocker, A.K., 2009, An investigation into the cladistic relationships and monophyly of therocephalian therapsids (Amniota: Synapsida). Zoological Journal of the Linnean Society, v. 157, p. 865891.CrossRefGoogle Scholar
Huttenlocker, A.K., 2013, The paleobiology of South African therocephalian therapsids (Amniota, Synapsida) and the effects of the end-Permian extinction on size, growth, and bone microstructure: Ph.D. Dissertation, University of Washington, Seattle, 414 pp.Google Scholar
Huttenlocker, A.K., and Botha-Brink, J., 2013, Body size and growth patterns in the therocephalian Moschorhinus kitchingi (Therapsida: Eutheriodontia) before and after the end-Permian extinction in South Africa: Paleobiology, v. 39, p. 253277.CrossRefGoogle Scholar
Huttenlocker, A.K., and Botha-Brink, J., 2014, Bone microstructure and the evolution of growth patterns in Permo-Triassic therocephalians (Amniota, Therapsida) of South Africa: PeerJ, v. 2, p. e325.CrossRefGoogle ScholarPubMed
Huttenlocker, A.K., Sidor, C.A., and Smith, R.M.H., 2011, A new specimen of Promoschorhynchus (Therapsida: Therocephalia: Akidnognathidae) from the Early Triassic of South Africa and its implications for theriodont survivorship across the Permian-Triassic boundary: Journal of Vertebrate Paleontology, v. 31, p. 405421.CrossRefGoogle Scholar
Ivakhnenko, M.F., 2011, Permian and Triassic therocephals (Eutherapsida) of eastern Europe: Paleontological Journal, v. 45, p. 9811144.CrossRefGoogle Scholar
Kemp, T.S., 1969, On the functional morphology of the gorgonopsid skull: Philosophical Transactions of the Royal Society of London: Series B, v. 256, p. 183.Google Scholar
Kemp, T.S., 1972a, Whaitsiid Therocephalia and the origin of cynodonts: Philosophical Transactions of the Royal Society of London: Series B, v. 264, p. 154.Google Scholar
Kemp, T.S., 1972b, The jaw articulation and musculature of the whaitsiid Therocephalia, in Joysey, K.A., and Kemp, T.S., eds., Studies in Vertebrate Evolution: New York, Winchester Press, p. 213230.Google Scholar
Kitching, J.W., 1977, The distribution of the Karroo vertebrate fauna: Memoir 1, Bernard Price Institute for Palaeontological Research, University of the Witwatersrand, 131 pp.Google Scholar
Laurin, M., 1998, New data on the cranial anatomy of Lycaenops (Synapsida, Gorgonopsidae), and reflections on the possible presence of streptostyly in gorgonopsians: Journal of Vertebrate Paleontology, v. 18, p. 765776.CrossRefGoogle Scholar
Maisch, M.W., 2002, Observations on Karoo and Gondwana vertebrates. Part 3: Notes on the gorgonopsians from the Upper Permian of Tanzania: Neues Jahrbuch für Geologie und Paläontologie, Monatshefte, v. 2002, p. 237251.CrossRefGoogle Scholar
Mendrez, C.H., 1972, On the skull of Regisaurus jacobi, a new genus and species of Bauriamorpha Watson and Romer 1956 (=Scaloposauria Boonstra 1953), from the Lystrosaurus-zone of South Africa, in Josey, K.A., and Kemp, T.S., eds., Studies in Vertebrate Evolution: Edinburgh, Oliver and Boyd, p. 191212.Google Scholar
Mendrez, C.H., 1974, A new specimen of Promoschorhynchus platyrhinus Brink 1954 (Moschorhinidae) from the Daptocephalus-zone (Upper Permian) of South Africa: Palaeontologia Africana, v. 17, p. 6985.Google Scholar
Owen, R., 1876, Descriptive and Illustrated Catalogue of the Fossil Reptilia of South Africa in the Collection of the British Museum: London, Printed by order of the Trustees.Google Scholar
Parrington, F.R., 1955, On the cranial anatomy of some gorgonopsians and the synapsid middle ear: Zoological Society of London Proceedings, v. 125, p. 140.CrossRefGoogle Scholar
Romer, A.S., 1969, The Chañares (Argentina) Triassic reptile fauna, V: A new chiniquodontid cynodont, Probelesodon lewisi—cynodont ancestry: Breviora, v. 333, p. 124.Google Scholar
Rubidge, B.S., 1995, Biostratigraphy of the Beaufort Group (Karoo Supergroup), South African Committee for Stratigraphy Biostratigraphic Series 1: Geological Survey of South Africa, 46 pp.Google Scholar
Rubidge, B.S., 2005, Reuniting lost continents—Fossil reptiles from the ancient Karoo and their wanderlust: South African Journal of Geology, v. 108, p. 135172.CrossRefGoogle Scholar
Rubidge, B.S., and Sidor, C.A., 2001, Evolutionary patterns among Permo-Triassic therapsids: Annual Review of Ecology and Systematics, v. 32, p. 449480.CrossRefGoogle Scholar
Sidor, C.A., Angielczyk, K.D., Weide, D.M., Smith, R.M.H., Nesbitt, S.J., and Tsuji, L.A., 2010, Tetrapod fauna of the lowermost Usili Formation (Songea Group, Ruhuhu Basin) of southern Tanzania, with a new burnetiid record: Journal of Vertebrate Paleontology, v. 30, p. 696703.CrossRefGoogle Scholar
Sidor, C.A., Vilhena, D.A., Angielczyk, K.D., Huttenlocker, A.K., Nesbitt, S.J., Peecook, B.R., Steyer, J.S., Smith, R.M.H., and Tsuji, L.A., 2013, Provincialization of terrestrial faunas following the end-Permian mass extinction: Proceedings of the National Academy of Sciences, v. 110, p. 81298133.CrossRefGoogle ScholarPubMed
Sigurdsen, T., Huttenlocker, A.K., Modesto, S.P., Rowe, T.B., and Damiani, R., 2012, Reassessment of the morphology and paleobiology of the therocephalian Tetracynodon darti (Therapsida), and the phylogenetic relationships of Baurioidea: Journal of Vertebrate Paleontology, v. 32, p. 11131134.CrossRefGoogle Scholar
Simpson, G.G., Roe, A., and Lewontin, R.C., 2003, Quantitative Zoology, revised edition: Mineola, New York, Dover Publications, Inc, 440 p.Google Scholar
Smith, R.M.H., and Botha, J., 2005, The recovery of terrestrial vertebrate diversity in the South African Karoo Basin after the end-Permian extinction: Comptes Rendus Palevol, v. 4, p. 623636.CrossRefGoogle Scholar
Smith, R.M.H., and Botha-Brink, J., 2014, Anatomy of a mass extinction: Sedimentological and taphonomic evidence for drought-induced die-offs at the Permo-Triassic boundary in the main Karoo Basin, South Africa: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 15, p. 99118.CrossRefGoogle Scholar
Tatarinov, L.P., 1995, Viatkosuchus sumini, a new Late Permian therocephalian from the Kirov region: Paleontological Journal, v. 29, p. 111128.Google Scholar
Ward, P.D., Botha, J., Buick, R., Dekock, M.O., Erwin, D.H., Garrison, G., Kirschvink, J., and Smith, R.M.H., 2005, Abrupt and gradual extinction among Late Permian land vertebrates in the Karoo Basin, South Africa: Science, v. 307, p. 709714.CrossRefGoogle ScholarPubMed
Watson, D.M.S., and Romer, A.S., 1956, A classification of therapsid reptiles: Bulletin of the Museum of Comparative Zoology, Harvard, v. 111, p. 3789.Google Scholar
Weide, D.M., Sidor, C.A., Angielczyk, K.D., and Smith, R.M.H., 2009, A new record of Procynosuchus delaharpeae (Therapsida, p. Cynodontia) from the Upper Permian Usili Formation, Tanzania: Palaeontologia Africana, v. 44, p. 2126.Google Scholar